/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.jobexecutor;

import org.activiti.engine.impl.cmd.ExecuteJobsCmd;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.interceptor.CommandExecutor;
import org.activiti.engine.impl.persistence.entity.JobEntity;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

/**
 * @author Tom Baeyens
 * @author Daniel Meyer
 * @author Joram Barrez
 */
public class ExecuteJobsRunnable implements Runnable {

    private static Logger log = LoggerFactory.getLogger(ExecuteJobsRunnable.class);

    private JobEntity job;
    private List<String> jobIds;
    private JobExecutor jobExecutor;

    public ExecuteJobsRunnable(JobExecutor jobExecutor, JobEntity job) {
        this.jobExecutor = jobExecutor;
        this.job = job;
    }

    public ExecuteJobsRunnable(JobExecutor jobExecutor, List<String> jobIds) {
        this.jobExecutor = jobExecutor;
        this.jobIds = jobIds;
    }

    public void run() {
        if (jobIds != null) {
            handleMultipleJobs();
        }
        if (job != null) {
            handleSingleJob();
        }
    }

    protected void handleSingleJob() {
        final SingleJobExecutorContext jobExecutorContext = new SingleJobExecutorContext();
        final List<JobEntity> currentProcessorJobQueue = jobExecutorContext.getCurrentProcessorJobQueue();
        final CommandExecutor commandExecutor = jobExecutor.getCommandExecutor();

        currentProcessorJobQueue.add(job);

        Context.setJobExecutorContext(jobExecutorContext);
        try {
            while (!currentProcessorJobQueue.isEmpty()) {

                JobEntity currentJob = currentProcessorJobQueue.remove(0);
                try {
                    commandExecutor.execute(new ExecuteJobsCmd(currentJob));
                } catch (Throwable e) {
                    log.error("exception during job execution: {}", e.getMessage(), e);
                } finally {
                    jobExecutor.jobDone(currentJob);
                }
            }
        } finally {
            Context.removeJobExecutorContext();
        }
    }

    protected void handleMultipleJobs() {
        final MultipleJobsExecutorContext jobExecutorContext = new MultipleJobsExecutorContext();
        final List<String> currentProcessorJobQueue = jobExecutorContext.getCurrentProcessorJobQueue();
        final CommandExecutor commandExecutor = jobExecutor.getCommandExecutor();

        currentProcessorJobQueue.addAll(jobIds);

        Context.setJobExecutorContext(jobExecutorContext);
        try {
            while (!currentProcessorJobQueue.isEmpty()) {

                String currentJobId = currentProcessorJobQueue.remove(0);
                try {
                    commandExecutor.execute(new ExecuteJobsCmd(currentJobId));
                } catch (Throwable e) {
                    log.error("exception during job execution: {}", e.getMessage(), e);
                } finally {
                    jobExecutor.jobDone(currentJobId);
                }
            }
        } finally {
            Context.removeJobExecutorContext();
        }
    }
}
